Anti-icing means for the air intake of gas turbines



C. W. HODGES ETAL ANTI-ICING MEANS FOR-THE AIR INTAKE OF' GAS TURBINES April 7, 1953 Filed Oct. 9, 1947 INVENTORS C-Hnmcsw. Houses .ElL-----wila-|-------------|--Jmm:

Patented Apr. 7, 1953 @UNITED y .sfrArEis l.PA'IE1SVI OFFICE ANTI-ICINGMEANS FOR THE .AIR INTAKE DE .GAS TURBINES Charles W. 'I-Iodgesf, Swarthmore, and Carl F'. Koenig III, Milmont Park, Pa., assignorsto VWestinghouse Electric'Corporation,.East Pittshurgln Pa. fa. Ycorporation` fof: Pennsylvania Application ,October 9, 1947,!Seria1No.778,830`

T Claims. (Cl. 23u-T32) sThisiinvention relates'to' aviatonpower' plants, and more particularly to 'means forrpreventing theicingof surfaces inthe air intake opening of van aircraft engine. y

Various more or less effective means Afor minlmizing they accumulation yofv ic'efon exposed intake lsurfaces Vof caviation power plants have been proposed.` "De-icing apparatusis particularly desirablefor'protection of the air intake vopening 'of av gasl turbine engineiof the typel Ycomprising va turbine-driven 'axial-now compressor, Which-is 'operable toV draw `large'volumes of' 'air from the latmosphere through the'forwardly directed intake opening forv delivery 'under pressure to the fuel combustion apparatus ofthe engine'. Thermal de-icirig 'of nose or spinner housing, struts, vduct entrances; Aand other structural Velements or fairi'ngs which protrude into the air intake opening' Vpassage Amay be accomplished by the use Aof a fluid medium, such as oil or gaswhich'is heated duringnormal operation vof the engine. n

rWepropose to' employ asimple Vand practicable cte-icing system for an' aircraft gas'turbine 'engine arranged for utilization .of hotV gas piped 'from a'point aft of the compressor, lpreferalcily the turbine outlet, to amanifold surrounding` the guide vanes or other elements exposed to the air'intake lpassageway of the engine. Certain features of 'the l present invention will, however. readily be' found'useful in ade-icing system of .thetype 'employing a heating 'fluid lother than -gas, vsuch as engine lubricating oil.

'It isthus an object of our invention to provide improved apparatus for preventing icing of the compressor inlet guide vanes, "fairing structure,

or other exposedportions ofthe air intake opening' of fan aviation power plant.

Another object of the invention is the provision of an improved de-icing apparatus for Va gas turbine engine 4includingannular manifolds mounted 'in the intake opening, and radial guide vanes having passages communicating with they manifolds for effecting circulation therethrough of heating fluid.

Still another object of the invention .is the provisionV of .an improved -apparatus for preventin'gicing of surfaces Withinan air intakepassageway, including guide vanes having communications through which heated fluid can be supplied to a vent port .located in advance of the usual central fairing section, whereby internal,

as well as` surface .heating of exposed elements can 'be effected.

These and other objects are eflectedby 'the invention as' will 'be apparent from the following description'and claims takenin connection with the `accompanying drawing, forming a partl of this application, in which:

Fig. 1 isa longitudinal, elevational View, main- 'ly in'section, of an aviation gas turbine/power plant having an inlet .portion "constructedin accordance with the invention;

Fig. 2 is `an enlarged detail fragmentary'view ofV the forward end of the apparatus-shownffin Fig. I1;

Fig. 3 is an enlarged detailed sectional view of one of the guide vanes shown in Fig. 2, taken along the line III-III thereof;

Figs. 4, 5 and 6 are Asectional views-of different` kformscf guide vanes which might be substituted for thatshown in Fig. 3; and

Fig. '7 isa fragmentary sectional View `:of the inlet vportion of a gas turbine engine similar'to that shown in Fig. 2, but employing' guidevanes having individual vent openings.

Referring nowto the drawing'in greater'detail, the gas'turbine engine illustrated in Fig. 1 'comprises a streamlined cylindrical outer casing ,structure I I which may be mounted in :orfonthe fuselage'of an aircraft, and which is adaptedzto house operating Aelements arranged in line to present minimum frontal 'area and drag 'during operation of the plane at high speed. Supported Within the casing structure His-an inner casing structure I2 forming an annular passageway I3, which constitutes a flow communication extend.- ing longitudinally through the engine from a'forwardly directed air intake opening I4 to a rearwardly disposed jet or discharge nozzle I5. Mounted within the casing structure I I--I2'a1ong `the axis thereof is a hollow fairing section I6, which may contain auxiliary control apparatus (not shown), a 'multiple 'stage axial flow compressor I'I, ,fuel combustion apparatus I8, vand .a turbine 25). The turbine 20 is operatively 'connected to the rotor of the compressor I'I through the. medium of an axially mounted shaft 22 which is suitably journaled within 'the inner casing structure I2. n f

In operation, air entering the intakeopening I 4. is compressed by the compressor I 'I and deliver-ed through the passageway I3 'to thecombustion apparatus I8, to support combustion of fuel therein while, at the same time, protecting adjacent surfaces of the power plant from the resulting 'high temperatures.v Hot motive fluid issuing from the combustion apparatus vI 8 is then .expanded through the turbine -2Il'and finally jdis'- charged through thenozzle "I5 in 'the form yoi a jet establishing the propulsive thrust. Since the general principles of operation of sucha gas turbine power plant are well understood, it is not deemed necessary to describe the functioning of the engine in further detail.

As ybest shown in Fig. 2 of the drawing, the portion of the outer casing structure II which defines the air intake opening I4 substantially surrounds the fairing section I5, which is, in

turn, carried as a part of the inner casing structure I2. In order to insure proper distribution of intake air flowing to the compressor, to turn the air to the proper angleV so that the air strikes the iirst rotating elements of the Vcoinpressor at the proper angle, a plurality of radially disposed stationary guide varies are interposed between the outer and inner casing structures, the opposite ends of the vanes being preferably welded to the corresponding portions of the respective casing structures. During operation `of a gas turbine engine in propelling a plane, large quantities of atmospheric air are necessarily drawn through the intake opening I4 past the fairing section I5 and associated guide vanes 25 and into the annular passagel.way I3, with the result that deposits of ice tend 4`to accumulate on the exposed surfaces. According to our invention, however, the guide 'varies 25 are provided with longitudinal passages for permitting circulation therethrough of heated fluid during operation o1" the invention, for 'preventing icing of the exterior surfaces of the vanes.

As shown in Fig. 3, each of the vanes 25 mal7 be made in the form of a hollow airfoil sheath -having a passage 26. To provide support for the vanes 25, yan annular inlet manifold 25 is Vmounted on the vouter casing structure II and welded to the outer ends of the varies. Formed in the manifold 28 is a passage 29 which communicates by way of a pipe 30 with a gas supply port 3| formed in the wall of the engine Vrearwardly of the turbine 25, as shown in Fig. l.. Ifz desired, a suitable control valve device 32 may be interposed in the pipe 35 for selective operation to control admission to the pipe of motive fluid at the will of the pilot. Mounted on the inner casing structure I2 concentrically .within the manifold 28, and welded to the in- ',neryends of the vanes 25, is an outlet manifold 5 Y ,34 having a passage 35, which communicates the forward or nose portion of the fairing section, and through which fluid may be vented into the stream of air drawn into the air intake opening I4. A cup-shaped shield 59 is preferably mounted in spaced relation with respect to the forward end of the fairing section It for guiding and insuring uniform distribution of yuid issuing from the port 38. The shield 39 may be supported on the fairing section I6 by means of a plurality of studs 40.

@From the foregoing, it will be apparent that .when the gas turbine engine is operated under conditions tending to induce icing of the fair- -ing section I5 and vanes 25, the control valve device 32 may be operated to supply hot motive fluid exhausted from the turbine 2B through the 4port 3|, pipe 3i), and manifold 28 to the respective passages 25 in the guide vanes 25, and

ithence by way of the inner manifold 34 and pipe 31 to the vent port 38, which is open to the air intake opening I4. Flow of hot motive fluid through the passages in the vanes 25 and pipe 31, aided by discharge flow of hot uid issuing from the portr3iil over the surface of the fairing section I1 and the vanes, will thus `be effective to prevent deposition of ice, without in any way impeding Vthe usual supply of atmospheric air through the intake opening I4.

In reducingour invention to practice, other types of guide vanes embodying features of the invention may be substituted for the guide vanes 25 shown in'Fig. 2. Referring to Fig. 4, there is illustrated a guide vane having a solid airfoil body portion on which is supported a substantially U-shaped leading wall 46, the rearwardlyV disposed edges of which are adapted to be Welded to the body portion to provide a flow passage 41. It will be understood that the iiow passage 41 is adapted to communicate with the respective passages 29 and 35 in the outer and inner'manifolds shown in Fig. 2.V

As shown in Fig. 5 of the drawing, a solid guide vane 49 may also be substituted for the .guide vane 25. The forward end of the guide vane 49 is provided with an arcuate groove into whichV is welded a tube 50, the passage 5I in which is adapted to communicate with the outer and inner manifolds already described.

Stillranother form of the invention is shown in Figure 6, in which is illustrated a solid guide 4vane 53 having a longitudinal bore 54 formed near the leading edge 55 thereof. In addition to communicating with the inner and outer manifolds 34 and 28, as explained in connection with Fig. 2, the bore 54 of the guide vane 53 is Vadapted to communicate directly with the passageway I3 of the engine by Way of a plurality Yof slots 55 formed in the surface of the vane adjacent the leading edge 55.

Illustrated in Fig. 7 of the drawing is a hollow guide vane 51, which may have the same construction as the vane 25 illustrated in Figs. l, 2 vand 3, but which is in addition provided with a vent opening 58 through which heated .fluid can be discharged from the passage within the vane into the annular passageway I3 of the engine.

' YIt will Ythus be seen that apparatus constructed in accordance with our invention, and ein- `bodying guide varies in any of the forms dis- '.closed, may be utilized to advantage in gasl tur- 'bine power plants of existing design as well as in engines in the process ofl development. The 'improved de-icing apparatus comprises a relatively small number of simply constructed and sturdy elements, which may be incorporated in the structure of the power plant without interference with the functioning of other parts thereof, and without adding to ,the weight of v the equipment.

While the invention has ybeen shown in several forms, it will be obvious to those skilled in Vthe art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What is claimed is:

l. Casing structure including a cylindrical section and a central fairing section forming an annular air intake opening, concentric annular manifolds mounted in said casing structure, hollow air guide vanes mounted radially within said intake opening and connecting said manifolds, a communication for supplying heated motive fluid to one of s aid manifolds, and a com- 5 munication for venting the other of said manifolds into said intake opening at a point near the nose portion of said fairing section, whereby heated motive fluid is supplied through the passages in said manifolds and blades and is diS- .charged over the surface of said fairing section for preventing icing Within said air intake Opening.

2. Casing structure including a cylindrical section and a central fairing section forming an annular air intake opening, concentric annular manifolds mounted in said casing structure, hollow air guide vanes mounted radially within said intake opening and connecting said manifolds, a communication for supplying heated motive fluid to one of said manifolds, a communication for venting the other of said manifolds into said intake opening at a point near the nose portion of said fairing section, and a cup-shaped shield supported in the front of said nose portion for directing hot motive iiuid back over the surfaces of said fairing section and guide vanes.

3. Casing structure including a cylindrical section and a central fairing section forming an annular air intake opening, outer and lmel manifolds mounted in said sections, respectively, a communication for supplying heated motive fluid to said outer manifold, another communication for venting said inner manifold into said intake opening in advance of said fairing section, and a plurality of guide vanes mounted radially within said intake opening, each of said vanes having a longitudinal passageway adapted to form a communication between said manifolds.

4. Casing structure including a cylindrical section and a central fairing section forming an annular air intake opening, outer and inner manifolds mounted in said sections, respectively, a communication for supplying heated motive fluid to said outer manifold, another communication for venting the other of said manifolds in advance of said fairing section, and a plurality of guide vanes mounted radially within said intake opening, each of said vanes having a tapered body portion supporting a tubular leading portion forming a longitudinal passageway for connecting said manifolds.

5. Casing structure including a cylindrical section and a central fairing section forming an annular air intake opening, outer and inner manifolds mounted in said sections, respectively, a communication for supplying heated motive uid to said outer manifold, another communication for ventingthe other of said manifolds in advance of said fairing section, and a plurality of guide vanes mounted radially within said intake opening, each of said vanes having a tapered airfoil body and a rounded leading' wall portion having edges secured thereto t0 form a longitudinal passageway adapted to connect said manifolds.

6. Casing stru-cture including a cylindrical section and a central fairing section forming an annular air intake opening, outer and inner manifolds mounted in said sections, respectively, a communication for supplying heated motive fluid to said outer manifold, another communication for venting the other of said manifolds in advance of said fairing section, and a plurality of guide vanes mounted radially within said intake opening, each of said vanes having an airfoil body having a longitudinal passageway formed therein for connecting said manifolds, said passageway also communicating with slots formed in said body and opening into said air intake opening.

7. Anti-icing structure comprising an outer cylindrical casing having an open end and a coaxially disposed core therein forming an annular air intake passage, concentric outer and inner annular manifolds supported in said casing adjacent said passage at a, substantial distance from the open end of said casing, a plurality of radially disposed guide vanes interposed in said passage between said manifoldss Said vanes having internal passages communicating with said outer and inner manifolds, means forming a supply communication for supplying hot motive gases to one of said manifolds, means forming -a vent .communication for discharging said gases from one of said manifolds at a point remote from said supply communication, said assemblage of manifolds and vanes providing a network of interconnected communications for circulation and exhaust of motive gases conducting heat thereto to prevent icing of surfaces exposed to said passage.

CHARLES W. HODGES. CARL F. KOENIG III.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PAI'EZN'I'Sy Weiler Feb. 17, 1948 

